Protective coating



Patented June 24, 1930 UNITED STATES LOUIS CLEVELAND JONES, F GREENWICH,CONNECTICUT PROTECTIVE COATING Ho Drawing.

My invention relates more particularly to protective coatings for use asa paint covermg on metals to prevent corrosion or applied as a water anddamp proof covering material on concrete, cement and similar surfaces.

Such improved coating is primarily in the nature of a water, alcohol orsimilar emulsion, such emulsions of asphalt and other bituminousmaterial having come into increased usage as coating materials. Uponevaporation of the water and alcohol, the asphalt or bitumen coalescesand gives an especially durable coating.

Such emulsions are generally made from a black material as a base, suchas asphalt, thereby making it exceptionally difficult or uite lmpossib eto impart desirable colors t ereto by the addition of pigments. It hasbeen found that the quantity of white or colored pi ment necessary toovercome the dense blacfi color of asphalt is so great as practically todestroy or impair the value of the materlal as a coating.

I have discovered in seeking a pigment to give color to such emulsifiedasphaltic and bituminous products that powdered or finely-dividedmetals, such as powdered metallic aluminum, mixed into such aqueous oralcoholic emulsions of coalescible hydrocarbons has the hithertoundiscovered and peculiar effect of maintaining the metallic lustre ofsuch owdered metal even when thoroughly mixed with a comparatively largeamount of emulsified material. In this way novel protective coatings maybe prepared which retain all the tenacity, elasticity and waterproofingeffects of asphalt, yet at the same time have a brilliant metalliclustre which covers the black surface obtained when asphalt alone isused. A vigorous stirring or mixing of the powdered metals in suchemulsions appears to coat the black particles of asphalt with themetallic powder which permits the use of a comparatively small amount ofthe finely-divided metal employed as such pigment.

I have also found that the final coating I mixture does not seem to behomogeneous since when applied to a glass surface the underside appearspractlcally black while Application filed November 21, 1925. Serial No.70,862.

the top surface exposed to the air shows only the metallic lustre. Suchsegregation of the metal in drying is of considerable advantagein'permitting the use of only a small amount of the powdered metal whichis the most expensive constituent of my improved coating. Such emulsionsof hydrocarbons or other bituminous materials in water or alcohol, ormixtures of same, form an exceptionally convenient medium for carryingpowdered metals to produce a lustrous protective coating which consistsbroadly of coalescible hydrocarbons emulsified in volatile liquid andcontaining sufiicient powdered metal to impart lustre, color, body, heatradiation or wearing properties.

The followin is an illustrative example of one method or producing suchimproved protective coating: An asphalt emulsion in water consistin offifty to sixty per cent of asphalt is use as a hydro-asphalt base. Theemulsifying agent may be soa plastic clay or similar compound capable oholding asphalt suspended as an emulsion in the water solution. Whenclay is used not to exceed ten per cent is sufficient. If the product isto be used in cold weather or to prevent freezing in storage, alcoholpreferably ethyl, may be added to replace a part of the water in theemulsion. To such hydro-asphaltic emulsion to form the protectivecoating having the lustre of metallic aluminum, I add from three to tenper cent by weight of aluminum powder which is first mixed with waterand stirred. The amount of water used is sufiicient when added to theemulsion to give the desired consistency to the entire mixture forconvenient application with a brush or spray. The aluminum powder mixesbetter with water if first moistened with alcohol. In some cases it isadvantageous to add enough alcohol with the aluminum powder to give aconsistency satisfactory for application and at the same time renderingthe mixture non-freezable.

Another coating composition, which I have found satisfactory, is formedfrom fifty percent linseed oil emulsified in water in any customary wayto which is added notexceeding five percent of powdered bronze metal. pa

The coalescible hydrocarbons which I may use include ordinary asphalt,bitumens, rubber latex, linseed 011, gums or resins which have beenemulsified in water, alcohol or other liquids which do not dissolve thehydrocarbons and which evaporate after the coating'has been applied. Theless the color of the emulsified hydrocarbon, the less the quantity ofmetal powder required to give the proper lustre. Copper, bronze or zincpowders may also be used having regard to their different specific'gravities, each imparting to the coating the peculiar advantage due tothe particular properties of the I metal utilized. For example, copperforms an excellent anti-fouling paint while zinc (due to galvanic actionwith iron tends to prevent corrosion. In all cases t e beneficiallustrous effect is produced by the metal powder coupled with therotective coating produced by the coalescible hydrocarbon base. In placeof ethyl alcohol, either pure or denatured methyl, propyl, or butylalcohol maybe used in substantially the same way that I havehereinbefore described.

I claim as my invention:

1. As a new composition of matter, a protective coating comprising anaqueous emulsion of coalescible hydro-asphalt to form the base mixedwith finely-divided particles of a.

metallic powder suspended in, and coating various particles of, saidbase, said metallicly coated particles being inherently floatable insaid emulsion.

2. As a new composition of matter, a protective coating comprising anaqueous emul-,

sion of coalescible hydro-asphalt to form the base mixed withfinely-divided particles of powered aluminum suspended in, and coatingvarious particles of, said base, said inetallicly coated particles beinginherently floatable in said emulsion.

3. As a new composition of matter, a protective coating comprising anaqueous emulsion of coalescible hydro-asphalt to form the base mixedwith finel -divided particles of powdered aluminum not to exceed ten percent by weight of said base) suspended in, and coating various particlesof said base, said metallicly coated particles being inherentlyfloatable in said emulsion.

LOUIS CLEVELAND J ONES.

